From: Eric W. Biederman <ebiederm@xmission.com>
Date: Sat, 6 Dec 2014 02:03:28 +0000 (-0600)
Subject: userns; Correct the comment in map_write
X-Git-Tag: v3.18.122~10
X-Git-Url: http://git.hungrycats.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8a749f3ef97796d702b2da4106459d46c5bb1adb;p=linux

userns; Correct the comment in map_write

commit 36476beac4f8ca9dc7722790b2e8ef0e8e51034e upstream.

It is important that all maps are less than PAGE_SIZE
or else setting the last byte of the buffer to '0'
could write off the end of the allocated storage.

Correct the misleading comment.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c
index a2e37c5d2f63..ad419b04c146 100644
--- a/kernel/user_namespace.c
+++ b/kernel/user_namespace.c
@@ -643,7 +643,7 @@ static ssize_t map_write(struct file *file, const char __user *buf,
 	if (!page)
 		goto out;
 
-	/* Only allow <= page size writes at the beginning of the file */
+	/* Only allow < page size writes at the beginning of the file */
 	ret = -EINVAL;
 	if ((*ppos != 0) || (count >= PAGE_SIZE))
 		goto out;